dspi.h

Freescale MCF5445evb 参考测试代码

/*!
 * \file    dspi.h
 * \brief   Driver for the DSPI module
 * \version $Revision: 1.2 $
 * \author  Michael Norman
 */

#ifndef _DSPI_H_
#define _DSPI_H_

#include "queue.h"

/*******************************************************************/

/*! List of the valid chip-selects on this master */
extern const uint8 dspi_valid_cs[];

/*! Enumeration for SPI Modes */
typedef enum spi_mode {
	SPI_MODE_0,     /*!< CPOL = 0; CPHA = 0 */
	SPI_MODE_1,	    /*!< CPOL = 0; CPHA = 1 */
	SPI_MODE_2,	    /*!< CPOL = 1; CPHA = 0 */
	SPI_MODE_3,	    /*!< CPOL = 1; CPHA = 1 */
} SPI_MODE;

/*! Enumeration for SPI first bit orientation */
typedef enum spi_fbit {
	SPI_FBIT_MSB,
	SPI_FBIT_LSB,
} SPI_FBIT;

/*! 
 * \struct spi_device
 * Structure that contains information about a device on the SPI bus
 */
typedef struct spi_device
{
    int         baud;           /*!< Default baud rate */
    SPI_MODE    mode;           /*!< CPOL and CPHA modes */
    SPI_FBIT    fbit;           /*!< First bit orientation, MSB or LSB */
    uint8       cs;             /*!< Chip-select physically connected to */
    uint8       cs_is;          /*!< CS inactive state; 1 = high, 0 = low */
    uint8       cs_muxed;       /*!< Use multiplexed chip-select encoding? */
    uint8       frame_size;     /*!< Number of bits transferred per frame */
    uint8       delay_csclk;    /*!< CS assertion to first CLK delay (ns) */
    uint8       delay_clkcs;    /*!< Last CLK to CS deassertion delay (ns) */
    uint8       delay_cscs;     /*!< CS to CS inactive time (ns) */
} SPI_DEVICE;

/*!
 * \struct spi_msg_link
 * Structure that contains information about an individual link in a message
 * chain. A message chain is made up of one or more message links.
 */
typedef struct spi_msg_link
{
    struct spi_msg_link *next;  /*!< Pointer to next link in the chain */
    void    *tx_buf;            /*!< Pointer to receive buffer (or NULL) */
    void    *rx_buf;            /*!< Pointer to receive buffer (or NULL) */
    int     length;             /*!< Length of transfer in bytes */
} SPI_MSG_LINK;

/*!
 * \struct spi_msg_chain
 * Structure that contains all the details about a chain of messages to be sent 
 * across the SPI bus. A message chain is made up of one or more message links.
 */
typedef struct spi_msg_chain
{
    QNODE           node;
    SPI_DEVICE      *device;    /*!< SPI device being communicated with */
    SPI_MSG_LINK    *link;      /*!< Pointer to message link */
    int             baud;       /*!< Special baud rate for this message */
    void (*callback)(struct spi_msg_chain *msg);  /*! Completion callback */
    uint8           use_dma;    /*!< To use DMA (TRUE) or not (FALSE) */
    vuint8          status;     /*!< Status of this message */
} SPI_MSG_CHAIN;

/*!
 * \struct spi_driver_data
 * Structure that holds data about the current state of the driver
 */
typedef struct spi_driver_data
{
    SPI_MSG_CHAIN   *chain;     /*!< Pointer to message in progress */
    QUEUE           queue;      /*!< Message queue */
    void            *tx;        /*!< Pointer to current tx position */
    void            *tx_end;    /*!< Pointer to end of tx buffer */
    void            *rx;        /*!< Pointer to current rx position */
    void            *rx_end;    /*!< Pointer to end of rx buffer */
    void            *last;      /*!< Pointer to last datum in the chain */
    int             status;     /*!< Driver status */
    
    /* Interrupt event counters */
    int         event_tc;       /*!< Transfer complete */
    int         event_eoq;      /*!< End of queue */
    int         event_tfu;      /*!< Transmit FIFO underflow */
    int         event_tff;      /*!< Transmit FIFO full */
    int         event_rfo;      /*!< Receive FIFO overflow */
    int         event_rfd;      /*!< Receive FIFO drain */
} SPI_DRIVER_DATA;
    
/* SPI Message status definitions */
#define SPI_MSG_CHAIN_IDLE      0
#define SPI_MSG_CHAIN_QUEUED    1
#define SPI_MSG_CHAIN_RUNNING   2
#define SPI_MSG_CHAIN_DONE      3

/* SPI Driver status definitions */
#define SPI_DRIVER_IDLE         0
#define SPI_DRIVER_RUNNING      1

/* Implementation specific define */
#define SPI_FIFO_SIZE           16

/*
 * Function prototypes
 */
int
spi_master_init(void);

int
spi_master_device_init (SPI_DEVICE *device);

int
spi_master_write(SPI_DEVICE *device, uint8 *tx_buf, int length);

int
spi_master_read(SPI_DEVICE *device, uint8 *rx_buf, int length);

int
spi_master_write_read(SPI_DEVICE *dev,  uint8 *txb, uint8 *rxb, int length);

int
spi_master_transfer(SPI_MSG_CHAIN *msg, int sync);

static int
spi_master_enqueue(SPI_MSG_CHAIN *msg);

__interrupt__
void spi_master_irq_handler (void);

static int
spi_master_tx (void);

static int
spi_master_rx (void);

/*******************************************************************/

#endif  /* _DSPI_H_ */